Filler coupling and corresponding receptacle and filling method

ABSTRACT

A filler-withdrawal coupling for a pressurized gas receptacle comprising a body defining an internal filler circuit between an upstream end designed to be connected to a packaging connector and a downstream end designed to be connected to a receptacle, the coupling comprising an isolation valve that can move relative to a seat between an upstream position for closing the circuit and a downstream position for opening the circuit, said isolation valve being moved to its upstream position by a return member, the coupling also comprising a dust-prevention valve placed upstream of the isolation valve, said dust-prevention valve being able to move relative to the body between an upstream position for closing the upstream end of the circuit and a downstream position for opening the circuit upstream end, said dust-prevention valve being moved to its upstream position by a return member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 13/168,532 filed Jun. 24, 2011 which claims the benefit of priority under 35 U.S.C. § 119 (a) and (b) to French Application No. 10 55605, filed Jul. 9, 2010, the entire contents of which are incorporated herein by reference.

BACKGROUND Field of the Invention

The present invention relates to a filler coupling, a tap, a pressurized fluid receptacle and a filling method using such a coupling.

The invention relates more particularly to a filler coupling for a pressurized gas receptacle designed to interact with a packaging connector in order to allow said receptacle to be filled, the coupling comprising a body defining an internal filler circuit between an upstream end designed to be connected to a packaging connector and a downstream end designed to be connected to a receptacle, the coupling comprising an isolation valve that can move relative to a seat between an upstream position for closing the circuit and a downstream position for opening the circuit, said isolation valve being moved to its upstream position by a return member, the coupling also comprising a dust-prevention valve placed upstream of the isolation valve, said dust-prevention valve being able to move relative to the body between an upstream position for closing the upstream end of the circuit and a downstream position for opening the circuit upstream end, said dust-prevention valve being moved to its upstream position by a return member.

The present invention concerns in particular a filler coupling comprising in series, from upstream to downstream (in the direction of a filling with gas), a dust-prevention valve and an isolation valve.

Related Art

The dust-prevention valve is provided notably to form a barrier upstream of the isolation valve to prevent or limit the intrusion of particles or of dust that may damage the sealing of said isolation valve.

A removable stopper or a dust-prevention valve is usually a good protection against the intrusion of foreign bodies into a filler coupling. However, this protection is not usually sufficient because, when the dust-prevention valve is open, particles can enter during the filling operation. These particles might in certain circumstances be brought in by the filling tool that delivers the filling gas.

This contamination of the isolation valve may cause a considerable leakage rate over the life of the product on which this filler coupling is installed. This is explained by the fact that the sealing zone of the contaminated isolation valve (dust, particles etc.) loses a large proportion of its sealing capability. This risk of intrusion of particles is increased when the filler coupling is vertical (filling from above).

Another solution consists in providing a filter for solid particles in the coupling upstream of the isolation valve. This makes it possible to trap particles or dust upstream of the isolation valve but does not make it possible to actuate the opening of the isolation valve by mechanical contact (the filter in fact forming a mechanical barrier for a valve driver).

Another solution consists in providing a filter downstream of the isolation valve. This allows the mechanical actuation of the isolation valve and provides dust protection for downstream of the isolation valve (the inside of the tap and the inside of the receptacle). However, the upstream end of the isolation valve is then subject to contamination by particles or dust that can affect its sealing.

SUMMARY OF THE INVENTION

One object of the present invention is to alleviate all or some of the drawbacks of the prior art listed above.

For this purpose, the coupling according to the invention, moreover conforming to the generic definition given to it by the above preamble, is essentially characterized in that the dust-prevention valve supports a filter interposed on the path of at least a portion of the fluid that travels between the upstream and the downstream of the circuit, the filter being able to move with the dust-prevention valve.

Therefore, according to the invention, a filtration device such as one or more filters is incorporated into a movable part which forms an upstream dust-prevention valve.

In this way, a double protective barrier is provided upstream of the isolation valve. Specifically, the body of the dust-prevention valve forms a first movable stopper at the upstream inlet of the coupling and the filter forms a second barrier which traps the particles when the dust-prevention valve opens the inlet of the coupling.

Moreover, this architecture with double valves and movable filter forms an effective protective mechanism in a filling process allowing improved protection of the downstream isolation valve.

The arrangement of the dust-prevention valve and of the movable filter interacts easily with various packaging connectors. Specifically, the dust-prevention valve and the movable filter move to allow opening of the upstream of the coupling while

-   -   protecting the downstream isolation valve from particles and     -   allowing the actuation of this downstream isolation valve by         mechanical contact.

The arrangement of the dust-prevention valve and of the movable filter also interacts easily with packaging connectors opening the isolation valve via a stream of pressurized gas delivered into the coupling (instead of a mechanical contact).

The arrangement of the coupling with double valves and movable filter thus provides a high level of protection of the isolation valve against dirt and offers opening sequences that are suitable for various types of filling.

The invention provides great safety in the opening/closing sequences of the filler coupling. Moreover, filling according to the invention keeps the coupling sealed throughout the life of the coupling.

Therefore, for example, and without being limiting, the upstream dust-prevention valve can advantageously participate in the mechanical opening of the downstream isolation valve by transmitting an opening force from upstream to downstream. That is to say, in certain filling configurations, the dust-prevention valve can form a member for transmitting movement between a packaging connector and the downstream isolation valve.

Similarly, the dust-prevention valve and the movable filter can ensure an opening of the upstream of the coupling allowing the downstream isolation valve to be opened with the pressure of the filling gas (as a function of the pressures and setting of the valves).

The upstream dust-prevention valve can therefore perform the following functions:

-   -   the opening/closing of the upstream of the circuit,     -   the filtration of the stream upstream of the downstream         isolation valve during a filling process, and, optionally,     -   the transmission of mechanical movement in order to selectively         control the opening or closing of the downstream isolation         valve.

According to possible particular features:

-   -   the dust-prevention valve comprises a downstream end and, when         said dust-prevention valve is in a determined downstream         position called “contact” position opening the upstream end of         the circuit, this downstream end of the dust-prevention valve         pushes an upstream end of the movable isolation valve in order         to move the isolation valve to its downstream position for         opening the circuit,     -   the coupling comprises one or more passageways for guiding at         least a portion of the stream of fluid travelling from upstream         to downstream through the filter,     -   the body of the dust-prevention valve slides in the circuit, the         passageway or passageways constricting the totality or virtual         totality of the fluid stream travelling from upstream to         downstream in the circuit to travel through the filter         irrespective of the downstream position of the dust-prevention         valve,     -   when the dust-prevention valve is in a determined downstream         position called “contactless” position opening the upstream end         of the circuit, the downstream end of the dust-prevention valve         does not push the upstream end of the isolation valve, the         upstream end of the isolation valve being capable of being         pushed to its downstream position for opening the circuit by the         pressurized fluid entering through the open upstream end of the         circuit,     -   the isolation valve can be moved selectively into a downstream         position for opening the circuit by mechanical actuation carried         out by the dust-prevention valve,     -   the isolation valve can be moved selectively into a downstream         position for opening the circuit by a pressurized fluid stream,     -   the dust-prevention valve can be selectively moved downstream by         a mechanical actuation and/or by pressurized fluid,     -   the filter comprises at least one filter for gas designed to         trap solid particles,     -   the dust-prevention valve comprises an upstream end that can be         actuated mechanically and/or via pressurized fluid,     -   the movable isolation valve comprises a flexible sealing gasket         designed to interact with the seat in order to achieve the         sealed closure of the circuit when the valve is moved against         the seat with a determined pressure,     -   in the upstream position for closing the upstream end of the         circuit, said dust-prevention valve closes off in a sealed         manner the inlet orifice of the circuit upstream end, for         example, in a watertight manner,     -   in the upstream position for closing the upstream end of the         circuit, said dust-prevention valve closes off in an unsealed         manner the inlet orifice of the circuit upstream end,     -   the body of the coupling and/or the dust-prevention valve         comprises a flexible lip forming a watertight barrier between         the body of the coupling and the dust-prevention valve at least         when the latter is in the upstream closed position,     -   the flexible lip comprises a free end allowing a gas or liquid         to pass when a determined pressure differential exists on either         side of the lip, in order notably to allow a possible discharge         of gas from downstream to upstream, for example in the event of         leakage of the isolation valve,     -   in the upstream position of the dust-prevention valve, the         upstream end of the dust-prevention valve recloses the upstream         end of the circuit in a flush manner at the upstream end of the         body of the coupling,     -   the body of the dust-prevention valve slides in a sealed manner         in the circuit,     -   the sealing between the dust-prevention valve and the body of         the coupling is achieved by metal/metal contact and/or via at         least one seal,     -   the passageway(s) comprise one or more internal ducts passing         through the body of the dust-prevention valve and/or passing         through the body of the coupling,     -   the passageway(s) comprise at least one space between the         dust-prevention valve and the body of the coupling in order to         force all or virtually all of the fluid stream passing from         upstream to downstream in the circuit to pass through the         filter,     -   the return member moving the isolation valve to its upstream         position comprises at least one of the following: a compression         spring, a tension spring,     -   the return member moving the dust-prevention valve to its         upstream position comprises at least one of the following: a         compression spring,     -   the downstream end of the dust-prevention valve comprises a rod         for mechanically actuating the upstream end of the isolation         valve,     -   the upstream end of the isolation valve comprises a surface         designed to interact in mechanical contact with the downstream         end of the dust-prevention valve,     -   the isolation valve is closed before the closure of the         dust-prevention valve,     -   the filter comprises at least one of: felt, a sintered metal, a         metallic or nonmetallic mesh, a structure with agglomerated         metallic or nonmetallic beads, metallic or nonmetallic threads,     -   the filter is moved with the dust-prevention valve during the         operations of opening and closing said valve,     -   the filter is placed on the dust-prevention valve downstream of         the upstream end of said valve,     -   the filter is not subjected to a direct mechanical contact from         a valve driver when the dust-prevention valve is driven         downstream by a valve driver of a filling connector,     -   the seat of the isolation valve is formed by a shoulder of a         tubular frame secured to the body of the coupling, the isolation         valve sliding in this frame, the downstream end of the         dust-prevention valve entering said frame when the         dust-prevention valve comes into the downstream position,     -   the coupling comprises an abutment designed to interact with the         dust-prevention valve in order to limit the maximum downstream         position of the latter,     -   the abutment designed to interact with the dust-prevention valve         in order to limit the maximum downstream position of the latter         is secured to the body of the coupling and/or to a frame secured         to the body and defining the seat of the isolation valve,     -   the isolation valve comprises a nonreturn mechanism generating a         force on the isolation valve and moving upstream when the latter         is subjected to a fluidic pressure in its upstream portion,     -   the nonreturn mechanism comprises a channel connecting the         upstream end of the isolation valve to a downstream chamber in         order to convert a fluidic pressure on the upstream portion of         the valve into a force on the downstream end of the isolation         valve tending to move said isolation valve into an upstream         closed position,     -   the nonreturn mechanism (“NRV”) comprises a determined         surface-area ratio between, on the one hand, the upstream end of         the isolation valve subjected to an upstream fluid and, on the         other hand, the downstream end of the isolation valve         communicating with the chamber, in order to move said isolation         valve into an upstream closed position when its upstream end is         subjected to pressurized fluid.

The invention also relates to a tap for pressurized fluid, in particular for pressurized gas, with or without pressure relief valve, comprising a filler coupling designed to interact with a packaging connector in order to allow the filling of said receptacle via said coupling, the filler coupling conforming with any one of the features above or below.

The invention also relates to a pressurized fluid receptacle, in particular a pressurized gas bottle, comprising a tap conforming with any one of the features above or below.

The invention also relates to a method for filling a pressurized gas receptacle conforming with any one of the features above or below by means of a packaging connector mechanically connected in a removable manner to said connector for filling the receptacle, the method comprising a first step of moving the dust-prevention valve and the filter to a downstream position for opening the upstream end of the circuit via a mechanical actuation and/or a fluidic actuation carried out by the packaging connector and a second step of moving the isolation valve to a downstream opening position via a mechanical actuation carried out by the dust-prevention valve and/or via a fluidic actuation carried out by the packaging connector.

According to other possible particular features,

-   -   the dust-prevention valve is moved downstream by a mechanical         action of an end of a valve driver belonging to the packaging         connector,     -   at the end of the process for filling a pressurized gas         receptacle, the isolation valve is automatically closed when the         mechanical force and/or the fluidic force exerted on the         upstream portion of the valve becomes less than a determined         threshold,     -   the external and/or internal surface of the body of the coupling         comprises stampings forming attachment recesses and/or reliefs         designed to interact with paired shapes of a packaging connector         to form a selective mechanical attachment system, notably a         quick connection system,     -   the filling method comprises a first step of moving the         dust-prevention valve and the filter to a downstream position         for opening the upstream end of the circuit via a mechanical         actuation and/or a fluidic actuation carried out by the         packaging connector and a second step of moving the isolation         valve to a downstream opening position via a mechanical         actuation carried out by the dust-prevention valve,     -   the valve or valves can be opened independently of the         mechanical attachment of the packaging connector to the         coupling, in particular, the valve or valves can be opened by         the packaging connector after the mechanical attachment of the         packaging connector to the coupling and via a distinct actuation         of the attachment system,     -   the packaging connector designed to interact with a filler         coupling of a pressurized fluid receptacle tap comprises at         least one gripper extending in a longitudinal direction about a         longitudinal axis, the central space situated between the         gripper or grippers and the longitudinal axis forming a housing         designed to accommodate a filler coupling of generally         cylindrical shape, the internal face of the at least one gripper         situated facing the central space comprising reliefs and/or         recesses of determined dimensions, the reliefs and/or recesses         being spaced relative to one another in a determined manner in         order to fit into grooves and/or paired reliefs formed on the         external face of a filler coupling, the at least one gripper         being able to move transversely relative to the longitudinal         axis between a position called “outspread” in order to allow the         insertion of a coupling into the central space and a position         called “closed” to allow the fitting of the internal face of the         grippers on the external face of a coupling, said connector         comprising a locking member that can move between an active         position immobilizing the grippers in the closed position and an         inactive position allowing the grippers to move toward the         outspread position.

BRIEF DESCRIPTION OF THE FIGURES

The invention may also relate to any alternative device or method comprising any combination of the features above or below.

Other particular features and advantages will appear on reading the following description made with reference to the drawings in which:

FIG. 1 represents a schematic view in section illustrating a first exemplary embodiment of a filler coupling according to the invention in a closed position,

FIG. 2 represents a schematic and partial view in section illustrating the filler coupling of FIG. 1 mounted on a receptacle tap in a position opened by the action of a packaging connector,

FIG. 3 represents a schematic and partial view in section illustrating the structure of a filler coupling according to the invention in a closed position (two valves closed),

FIG. 4 represents the filler coupling of FIG. 3 in an open position (two valves opened by mechanical contact),

FIG. 5 represents the filler coupling of FIG. 3 in an open position (two valves opened respectively by gas pressure and by mechanical contact),

FIG. 6 represents the filler coupling of FIG. 3 in an open position (two valves opened respectively by mechanical contact and by gas pressure),

FIG. 7 represents the filler coupling of FIG. 3 in an open position (two valves opened by gas pressure),

FIG. 8 represents a schematic view in section illustrating a second exemplary embodiment of a filler coupling according to the invention in a closed position,

FIG. 9 represents an enlarged view in section of a detail of the upstream end of a filler coupling illustrating another possible exemplary embodiment of the upstream valve in the closed position),

FIG. 10 represents the filler coupling of FIG. 3 in a closed test position (upstream valve open and downstream valve closed).

DETAILED DESCRIPTION OF THE INVENTION

Now with reference to FIG. 1, the filler coupling 1 comprises a body 2, for example of generally cylindrical shape. The body 2 defines an internal filling circuit 6 between an upstream end 3 designed to be connected to a packaging connector and a downstream end 4 designed to be connected to a pressurized gas receptacle (via for example an internal circuit of a tap).

The terms “upstream” and “downstream” define the flow of a filling gas from a packaging connector to the inside of a receptacle.

The upstream end 3 of the circuit 6 (and of the coupling 1) can be selectively closed by a dust-prevention valve 10 which can move in the body 2 of the coupling.

The dust-prevention valve 10 can be selectively moved in the body 2 (preferably in translation) between an upstream position for closing the upstream end 3 of the circuit 6 and a downstream position for opening the circuit upstream end 3. Preferably, the dust-prevention valve 10 is moved to its upstream position by a return member 14, for example a spring such as a compression spring.

Preferably, in the upstream position for closing the upstream end 3 of the circuit 6, the dust-prevention valve 10 is housed in the body 2 of the coupling and is flush with the end surface of the body 2 of the coupling 1.

The dust-prevention valve 10 closes the upstream inlet 3 of the circuit in a sealed or unsealed manner by contact with the body 2 of the coupling 1. The body of the dust-prevention valve 10 may comprise one or more seals 105 closing off the circuit 6 in a sealed manner.

The dust-prevention valve 10 moreover supports a filtering element such as one or more filters 102 designed to trap solid particles having a dimension greater than a determined threshold. For example, the filter or filters 102 trap the particles that have dimensions greater than 0.1 mm or greater than 0.05 mm or greater than 1 mm or greater than 1 mm or greater than 2 mm or greater than 3 mm (depending on requirements or depending on the applicable standard: medical or industrial). Naturally, the invention is not limited to these precise examples and the filter may be designed to trap particles of a smaller or larger size than the above examples.

The filter 102 comprises for example at least one amongst: felt, a porous structure made of sintered metal, one or more metallic and/or nonmetallic meshes, a porous structure with agglomerated metallic or nonmetallic beads, metallic or nonmetallic threads or any other appropriate filter according to the application (as a nonlimiting example, see the filters from “Copor”).

The filter 102 can be moved with the dust-prevention valve 10. The filter 102 is interposed on the path of at least a portion of the fluid that travels between the upstream 3 and the downstream 4 of the circuit 6.

Accordingly, the dust-prevention valve 10 may comprise one or more passageways 103 guiding at least a portion and preferably all of the fluid stream travelling from upstream 3 to downstream 4 through the filter 102. That is to say that, when a gas travels from upstream 3 to downstream 4, the passageway(s) 103 force the totality or the virtual totality of the gas stream to pass through the filter 102 irrespective of the downstream position of the dust-prevention valve 10. The passageways 103 may comprise internal ducts passing through the body of the valve 10. As a variant or in combination, it is possible to envisage ducts or passageways passing through the body 2 of the coupling 1. Similarly, as a variant or in combination, it is possible to envisage one or more passageways 103 formed by a spacing between the dust-prevention valve 10 and the body 2 of the coupling.

The clogging of the filter 102 can be limited by subjecting the filter 102 to bleeding streams (from downstream to upstream). This can notably be provided during a filling operation or before a filling. In this manner, the filter 102 can be cleared of at least a portion of the particles trapped in the filter during a previous filling.

The filter 102 can be attached removably or irremovably to the dust-prevention valve 10. For example, the filter 12 is crimped into the body of the dust-prevention valve 10. It is possible to envisage the filter 102 being removable and replaceable. For example, the filter 102 is replaced or cleaned according to a maintenance procedure periodically in order to discharge the trapped dust or impurities and thus ensure that the isolation valve 7 downstream is protected at all times (in order also to limit the risks of adiabatic compression for example). As a variant, to change filter, the dust-prevention valve 10 can be replaced. As a variant, the coupling is replaced in its entirety.

Downstream of the dust-prevention valve 10, the circuit 6 contains an isolation valve 7 that can move relative to a seat 8. The isolation valve 7 can be moved preferably in translation between an upstream position for closing the circuit and a downstream position for opening the circuit. The isolation valve 7 is moved by default toward its upstream position by a return member 9 such as a spring notably a compression spring.

As shown, the isolation valve 7 may comprise a flexible sealing gasket 17 designed to interact with the seat 8. The flexible gasket may contain plastic, a polymer, a cured elastomer or any other appropriate material.

As shown, without it being necessary, the seat 8 of the isolation valve 7 can be formed by an annular shoulder secured to a tubular frame 15 fixed in the body 2 of the coupling (for example by sealed screwing). For example, the isolation valve 7 slides in this frame 15. One end 16 of this frame 15 or of the seat 8 can for example form an abutment 16 designed to interact with the dust-prevention valve 10 to limit the maximum downstream position of the latter. Similarly, the spring 14 of the dust-prevention valve can rest on this frame 15.

Therefore, the dust-prevention valve 10 comprises an upstream end or surface 104 that can be actuated mechanically (that is to say by mechanical contact) and/or via pressurized fluid.

Preferably, the filter 102 is placed on the dust-prevention valve 10 downstream of the upstream end 104 of said valve 10. In this way, the filter 102 is not directly subjected to a mechanical contact or to a pressure when the dust-prevention valve 10 is pushed downstream.

In FIG. 2, the coupling 1 is shown schematically on a tap 12 of a receptacle 13. Moreover, a packaging connector 11 opening the coupling 1 is shown symbolically in dashed lines.

Preferably, the external surface of the body 2 of the coupling 1 comprises stampings 116 forming attachment recesses and/or reliefs designed to interact with paired shapes of a packaging connector 11 in order to form a mechanical attachment system, notably a quick connection system (not shown in detail). In particular, preferably the stampings 116 are of a dimension and are positioned according to a determined geometry preferably in order to fit a determined paired packaging connector 11 (and only that connector).

As shown in FIG. 2, the dust-prevention valve 10 can be moved selectively downstream by a mechanical actuation, for example by a valve driver 111 that can be moved selectively in response to an actuator such as a pivoting lever 204 for example. The movement of the valve driver 111 can be obtained also automatically, for example pneumatically or and/or by an electromechanical system.

The valve driver 111 is preferably inserted into the coupling in a sealed manner and delivers pressurized gas via an internal or external channel to the valve driver 111 (not shown).

As can be seen in FIG. 2, when the dust-prevention valve 10 is brought to a determined downstream position called the “contact” position (with the upstream end 3 open), a downstream end 101 of the dust-prevention valve 10 pushes an upstream end 107 of the isolation valve 7 in order to move the isolation valve 7 toward its downstream position for opening the circuit 6.

That is to say that the isolation valve 7 can be moved selectively into a downstream position for opening the circuit by mechanical actuation carried out by the dust-prevention valve 10.

Accordingly, as shown in the figures, the dust-prevention valve 10 may comprise a downstream end 101 in the form of a rod the terminal surface of which is designed to mechanically actuate the upstream end of the isolation valve 7. The upstream end of the isolation valve 7 may also be formed by a rod which protrudes in the upstream direction relative to the seat 8 of generally annular shape.

Therefore, from a closed position (dust-prevention valve 10 closed F and isolation valve closed F) illustrated schematically in FIG. 3, a packaging connector 11 can mechanically push the upstream end 104 of the dust-prevention valve 10 (pressure P). The dust-prevention valve 10 and the filter 102 are moved in the downstream direction. The inlet of the circuit 6 of the coupling 2 is open (FIG. 4). The downstream end 101 of the dust-prevention valve 10 in its turn pushes the upstream end 107 of the isolation valve 7 (mechanical pressure P) which then opens the downstream end of the circuit 6. The stream of pressurized gas can travel from upstream to downstream (symbolized by the arrows).

Naturally, this method of opening and of filling is not limited to this example. Therefore, as shown in FIG. 5, depending on the filling conditions, the upstream end 104 of the dust-prevention valve 10 can be pushed in the downstream direction by the gas stream itself (symbolized by arrows). The downstream end 101 of the dust-prevention valve 10 can then mechanically push (pressure P) the isolation valve 7.

In the variant of FIG. 6, the dust-prevention valve 10 is opened (O) mechanically by a packaging connector 11 (pressure P) but the isolation valve 7 is opened (O) not by the downstream end 101 of the dust-prevention valve 10 but by the force exerted by the pressure of the incoming gas.

In the variant of FIG. 7, the dust-prevention valve 10 and the isolation valve 7 are opened (O) by the force exerted by the pressure of the filling gas.

Therefore, it is easy to understand that, depending on the geometry of the filling connector and the filling conditions (notably the flow rate and the pressure of the filling gas inserted into the coupling by the filling connector 11), the two valves 10, 7 in series can be opened (moved in the downstream direction) by a mechanical contact and/or by the pressure of the filling gas.

This confers great flexibility of use on the coupling according to the invention. Specifically, filling with gas in all cases ensures that the gas is filtered upstream of the isolation valve 7. Moreover, the filter 102 does not oppose the mechanical actuation of the dust-prevention valve 10.

Moreover, the opening of the coupling when filling can be obtained by a sequential opening of the two valves 10, 7 in series (first the dust-prevention valve 10, then the isolation valve 7).

At the end of a filling process of a pressurized gas receptacle, the isolation valve 7 is closed automatically by the action of the spring 9 when the mechanical and/or fluidic force exerted on the upstream portion of the valve 7 falls below a determined threshold. At the end of the filling operation, the isolation valve 7 is closed in principle before the dust-prevention valve 10 is closed.

The structure according to the invention also makes it possible to put in place filling procedures that are particularly effective in terms of safety for the operators carrying out the filling and for the end users of the tap fitted with such a coupling.

Therefore, for example, the movable dust-prevention valve 10 adopts, during its movement, at least two sealed positions making it possible to ensure secure filling.

In a first sealed position, the dust-prevention valve 10 is moved in the downstream direction and opens the upstream of the circuit 6 without the isolation valve 7 being opened (see FIG. 10). In this open position (O) of the upstream valve 10 and the closed position (F) of the downstream valve 7, the chamber situated upstream of the isolation valve 7 can be evacuated (determined low pressure) for example by a filling tool in order to carry out tests prior to filling. In this configuration, it is actually possible to measure any leaks originating from the isolation valve 7.

In another sealed position, the isolation valve 7 can also be opened in order to carry out a filling and/or to carry out a possible emptying of the circuit 6 and of the bottle before filling (see for example the configuration of FIG. 4, but with a gas stream reversed in the event of draining).

At the end of filling, the isolation valve 7 can be closed again and the dust-prevention valve 10 can be kept open (see FIG. 10) to carry out possible sealing tests at the end of filling such as those described above prior to filling.

FIG. 8 illustrates a variant embodiment of the invention which differs from that described above only in that the isolation valve 7 comprises a nonreturn mechanism 7, 177 (“NRV”=“nonreturn valve”).

For the purposes of being concise, the same elements as those described above are indicated by the same reference numbers and are not described a second time.

The nonreturn mechanism 7, 177, known per se, comprises a system generating a force on the isolation valve 7 pushing it upstream when the latter is subjected to a fluidic pressure in its upstream portion.

That is to say that the nonreturn mechanism 7, 177 is designed to allow the isolation valve 7 to be opened only by pressure via a mechanical contact (and not via a fluidic pressure).

The nonreturn mechanism comprises for example a channel 77 connecting the upstream end 107 of the isolation valve 7 to a sealed downstream chamber 277. This architecture converts a fluidic pressure on the upstream portion 107 of the valve 7 to a force on the downstream end of the isolation valve 7 tending to move said isolation valve 7 into an upstream position for closure. Accordingly, the nonreturn mechanism comprises a determined ratio of surface areas between, on the one hand, the upstream end 107 of the isolation valve 7 subjected to an upstream fluid and, on the other hand, the downstream end of the isolation valve 7 communicating with the chamber 277. In this way, the isolation valve 7 is moved into an upstream position for closure when its upstream end is subjected to pressurized fluid.

A method of filling via the coupling of FIG. 8 may comprise a first step of moving the dust-prevention valve 10 and the filter 102 to a downstream position for opening the upstream end of the circuit 6 via a mechanical actuation and/or a fluidic actuation. On the other hand, the isolation valve 7 can be opened only mechanically by a pushing force made by the dust-prevention valve 10.

These filling methods make it possible to ensure safe filling and the maintained sealing of the coupling after many fills.

The variant of FIG. 9 differs from that of FIG. 1 only in that the body 2 of the coupling 1 comprises a flexible lip 27 the free end of which interacts with the dust-prevention valve 10 in order to form a watertight barrier between the body 2 of the coupling and the dust-prevention valve 10 (at least when the latter is in the upstream closed position).

The flexible lip 27, which preferably has an annular shape around the dust-prevention valve 10, is for example made of elastomer fitted or cured onto the body 2.

The flexibility of the lip 27 is designed to prevent ingress of water in the downstream direction while all the same allowing fluid (gas notably) to pass in the event of determined pressure (notably in the event of leakage of the isolation valve 7).

The use of this coupling on gas taps preferably furnished with pressure relief valves offers many advantages. Specifically, the gas receptacles (bottles for example) furnished with such taps can be filled in total safety and can retain one and the same filler coupling without endangering the seal of the coupling.

The filling method according to the invention therefore makes it possible to improve the protection of the sealing valve gasket from contamination (metal particles, dust etc.) via the movable filter that is moved during filling.

This makes it possible to increase the reliability of the seal of the coupling throughout the life of the tap and of the bottle fitted therewith.

According to the invention, the mechanical pushing of the isolation valve 7 remains possible despite the presence of the filter 102 upstream.

Irrespective of the presence of a movable filter on the dust-prevention valve 10 (the filter can be omitted), the filling method according to the invention therefore makes it possible to improve the safety of filling via the actuation of the in-series double-valve mechanism described above.

Advantageously the invention applies to the filler couplings and filling systems for pressurized gas bottles, for example between 150 and 750 bar, fitted with taps with integrated relief valves or with removable relief valves.

In a possible variant, the movable filter could be omitted from the dust-prevention valve 10.

The filler coupling may if necessary also be the gas drainage coupling.

It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above. 

What is claimed is:
 1. A filler and withdrawal coupling for a pressurized gas receptacle designed to interact with a packaging connector in order to allow said receptacle to be filled and for gas to be withdrawn, the coupling comprising a body defining an internal withdrawal circuit between an upstream end adapted to be capable of connecting to a packaging connector and a downstream end adapted to be capable of connecting to a receptacle, the coupling comprising an isolation valve that is capable of moving relative to a seat between an upstream position capable of closing the internal withdrawal circuit and a downstream position capable of opening the internal withdrawal circuit, said isolation valve adapted to be moved to its upstream position by a return member, the coupling also comprising a dust-prevention valve placed upstream of the isolation valve, said dust-prevention valve being capable of moving relative to the body between an upstream position capable of closing the upstream end of the internal withdrawal circuit and a downstream position capable of closing opening the internal withdrawal circuit upstream end, said dust-prevention valve capable of closure by being moved to its upstream position by a return member, wherein the dust-prevention valve comprises a filter interposed on the path of at least a portion of the internal withdrawal circuit, the filter being adapted to move with the dust-prevention valve.
 2. The coupling as claimed in claim 1, wherein the dust-prevention valve comprises a downstream end and said dust-prevention valve is capable of occupying a contact position wherein the downstream end of the dust-prevention valve is capable of operably interacting with an upstream end of the movable isolation valve to thereby move the isolation valve to its downstream position thereby opening the internal withdrawal circuit.
 3. The coupling as claimed in claim 1, wherein one or more passageways are adapted to guide at least a portion of a stream of fluid travelling from upstream to downstream through the filter.
 4. The coupling as claimed in claim 3, wherein the body of the dust-prevention valve is capable of sliding in the circuit and the passageway or passageways are adapted to constrict the totality or substantial totality of a fluid stream travelling from upstream to downstream in the internal withdrawal circuit and are further adapted to direct the fluid stream through the filter irrespective of the downstream position of the dust-prevention valve.
 5. The coupling as claimed in claim 1, wherein the dust-prevention valve is adapted to be capable of occupying a contactless position, the contactless position configured to open the upstream end of the internal withdrawal circuit, the contactless position comprising a downstream end of the dust-prevention valve not in contact with the upstream end of the isolation valve, wherein the upstream end of the isolation valve is capable of being pushed to its downstream position for opening the internal withdrawal circuit by the pressurized fluid entering through the open upstream end of the circuit.
 6. The coupling as claimed in claim 1, wherein the isolation valve is capable of being moved selectively into a downstream position for opening the circuit by a mechanical actuation by the dust-prevention valve.
 7. The coupling as claimed in claim 1, wherein the isolation valve is capable of being moved selectively into a downstream position for opening the circuit by a pressurized fluid stream.
 8. The coupling as claimed in claim 1, wherein the dust-prevention valve is capable of being selectively moved downstream by a mechanical actuation and/or by pressurized fluid.
 9. The coupling as claimed in claim 1, wherein the filter comprises at least one filter for a gas and is adapted to trap solid particles in the gas.
 10. A tap for pressurized fluid, comprising the coupling of claim 1 and adapted to interact with a packaging connector in order to allow the withdrawal of gas from said receptacle via said coupling.
 11. A pressurized gas receptacle, comprising the tap of claim
 10. 12. A method for withdrawing gas from the pressurized gas receptacle of claim 11 by a packaging connector mechanically connected in a removable manner to said connector for withdrawal of gas from the receptacle, wherein the method comprises a first step of moving the dust-prevention valve and the filter to a downstream position for opening the upstream end of the circuit via a mechanical actuation and/or a fluidic actuation carried out by the packaging connector and a second step of moving the isolation valve to a downstream opening position via a mechanical actuation carried out by the dust-prevention valve and/or via a fluidic actuation carried out by the packaging connector.
 13. The method as claimed in claim 12, wherein the dust-prevention valve is moved downstream by a mechanical action of an end of a valve driver belonging to the packaging connector.
 14. The method as claimed in claim 12, wherein at the end of the process, the method comprises a further step of automatically closing the isolation valve when the mechanical force on and/or the fluidic force exerted on the upstream portion of the valve becomes less than a determined threshold.
 15. The method as claimed in claim 12, wherein the external and/or internal surface of the body of the coupling comprises stampings forming attachment recesses and/or reliefs designed to interact with paired shapes of a packaging connector to form a selective mechanical attachment system.
 16. The method as claimed in claim 12, wherein the method comprises a first step of moving the dust-prevention valve and the filter to a downstream position for opening the upstream end of the circuit via a mechanical actuation and/or a fluidic actuation carried out by the packaging connector and a second step of moving the isolation valve to a downstream opening position via a mechanical actuation carried out by the dust-prevention valve. 